The present invention relates to methods and devices for separating ions from a fluid stream.
Seawater contains several salts, including sodium chloride (table salt), calcium chloride, calcium sulfate (gypsum), magnesium chloride, magnesium sulfate, potassium chloride (sulfite or so-called xe2x80x9clight saltxe2x80x9d) and potassium sulfate. These salts are present in ions, including the cations sodium, potassium, magnesium, calcium, and the anions, chloride, bicarbonate and sulfate.
In addition to these major ions, seawater contains trace amounts of virtually every element found in nature, including gold, silver, platinum, manganese, lead, iron, and iodine. Some of these elements are intrinsically valuable, such as the precious metals. Others are useful in science and industry. Still others are toxic if consumed.
Accordingly, ion-separation systems are useful for producing desalinated or xe2x80x9clow-ionxe2x80x9d fresh water for drinking and irrigation. Ion-separation systems may be used to capture valuable elements, such as gypsum and precious metals. Still further, ion-separation systems may be used to remove toxic elements for water and other fluids.
While there are processes for separating ions from seawater and other fluid streams, there remains a need for an ion separation system which requires little positive energy input. There is a need for an ion separation system that requires no thermal input. There is a need for an ion separation system that can be adapted for a variety of purposes. Still further, there is a need for a system that can process large volumes at relatively low cost.
The present invention comprises an apparatus for separating ions from a fluid stream comprising one or more ionized salts. The apparatus comprises an electrically non-conductive and non-magnetic fluid conduit defining a fluid path for a fluid stream flowing therethrough. The conduit defines an influent path, a processing zone, a low-ion effluent path downstream of the processing zone, a cation effluent path downstream of the processing zone, and an anion effluent path downstream of the processing zone. The fluid path in the processing zone has a flow vector.
The apparatus further comprises a magnetic field generator adapted to establish a magnetic field across the processing zone of the conduit so that the flux lines of the generated magnetic field are generally perpendicular to the flow vector of the fluid path in the processing zone. Still further, the apparatus includes an electrostatic field generator adapted to establish a generally linear electrostatic field across the processing zone. The electrostatic field has a vector perpendicular to the flow vector of the fluid path in the processing zone and to the flux lines of the magnetic field.
The present invention further comprises a method for separating ions from a fluid stream. The method comprises flowing a fluid in a stream along a fluid path in a processing zone, the fluid path having a flow vector. The fluid stream in the processing zone is exposed to a magnetic field in which the flux lines are substantially perpendicular to the flow vector of the fluid path. Simultaneously, the fluid stream is exposed to a substantially linear electrostatic field perpendicular to the flow vector of the fluid path and to the vector of the flux lines of the magnetic field.